Sathianbun, Sarayut

Abstract [en]

Self-compacting concrete has soon been around for a decade. Recently the prefabrication industry has started to use this fairly new concrete type in larger scales, mainly because of its distinctive properties. There are still certain areas that need to be thoroughly examined, such as bond capacity. There have been very few studies regarding shear capacity due to the fact that the procedure is complicated.

This report will highlight a method to examine the shear capacity of different surfaces that have been prewetted as well as non-prewetted surfaces. The surface areas follow BBK 04’s and Eurocode 2’s demand for surface roughness. A smooth surface will be completed in order to confirm if the different shapes influence the bond strength by shear stress or not.

The purpose of this essay is to measure the bond strength within the shear capacity as well as examine the impact it has on surface roughness and treatment for shear bond.

The method used to identify the shear capacity is called L-shaped Push-Off Test. The dimension of the object was selected with the help of a previous research paper. The Sand-Patch method is predominantly used to measure the surface roughness.

The results showed no difference between the demands of surfaces of BBK04 and Eurocode 2 considering the shear capacity. However the non-prewetted surface was measured with the highest shear capacity value. Apart from the shear strength, deformation was measured in both vertical and horizontal direction and it was clearly shown that the vertical deformation was measured to be ten times higher than the horizontal deformation. There was no difference between the BBK 04 and Eurocode 2 considering the vertical deformation. However the difference occurred on the horizontal direction between BBK 04 and Eurocode 2 where the specimens of Eurocode 2 received three times higher deformation compared to BBK 04. The conclusion can be drawn that the surface roughness of BBK 04 would be more suitable than eurocode2 considering deformation.

The overall result was that the surface treatment with the demands of BBK 04 and Eurocode 2 showed minor difference after being measured with the Push-Off Test method. This has been confirmed with the estimated shear capacity (1.2 MPa). The results revealed that the treatment of surface could be made in either way, brush or rake. As a conclusion the assessment of the shear strength showed that Eurocode 2's demand is too strict comparing demands of BBK 04.